Variable capacity lubricating pump



Patented-Mai'.` "7, 1950 I VARIABLE-CAPACITY LUBRICATING PUMP Eugen'Schmidt, Winter-thur, Switzerland,` assignor to Sulzer Freres, SocieteAnonyme, Winte'thur, Switzerland Application September 20, 1945, SerialNo. 617.647 In Switzerland November 16, 1943 Section 1, Public Law 690,August 8, 1946 e Patent expires November 16, 1963 3 Claims. l

The invention relates to a lubricating apparatus and its purpose is toreduce the width of the pump set and to simplify manufacture. Itconsists in that a pump set interchangeable as a whole is provided atleast with one feed pump and one high-pressure l'ubricating pump whichare connected by an overflow passage in which is provided an adjustablemember for measuring the quantity of lubricating medium, the bores forthe pistons, their guide means and the overflow passage being arrangedin the same plane. It is preferable for the cylinder of the highpressurepump to be inserted in the pump set so as to be individually'interchangeable.

One embodiment of the invention is shown diagrammatically in thedrawing.

The figure shows in cross-sectional elevation a lubricating apparatuswith the container I in which are inserted a number of pump sets 2 whichcan be interchanged as a whole and whose joints with the container areoil-tight. All the pump sets are driven by the driving shaft 3, a crank4 being provided for each pump set 2. The shaft 3 is driven in a knownmanner and at constant speed by the engine to be lubricated, or if thedrive is taken from a reciprocatng part the shaft 3 is equipped with aratchet drive. The lubricating oil is introduced into the container lthrough the filling opening 5 with a filter 6. Each pump set 2 has atleast one feed pump and one high-pressure lubricating pump in the casing3 which is attached to the container l by means of bolts 9. The feedpump has a piston o in the bore ll, and this controls the suctionpassage !2. Beside the feed pump o, Il is the bore l4 for the guidebushing !5 in the drive for the high-pressure piston l6, which works inthe cylinder ll of the high-pressure pump arranged in the casing 8 so asto be interchangeable. The guide bushing !5 has an open-ended'scotchyoke surrounding the crankpin 4, and to this yoke the piston o of thefeed pump is also attached. The yoke lB is open at one side in order toallow the set 2 to be removed without dismantling, the shaft 3.

The feed pump o, ll is connected to the highpressure pump !6, ll througha passage consisting of the delivery bore |3 connecting up to the borell (the two parts of the bore !3 being connected by the recess l9 in thebushing !5) of the outlet with the non-return valve 2l and the discharge22, of the chamber 23 with the sight glass 24, and finally of thesuction passage 25 of the high-pressure pump !6, ll. The bores for thepistons n and !6. the bushins guide I! and the stroke.

passage !3, |9--25, are arranged in the same plane.

In the upper part of the delivery bore l3 is provided the meteringpiston 26 which is pressed down by* means oflthe spring 21 as a pistonopposed to the feed piston o. The piston 26 is provided with a bore 728which communicates through the transverseports 29 with the returnpassage 30 in the casing 8.

The high pressure cylinder I'I is equipped with two delivery valves 3|and 32 which communicate with the pipe 33 for the lubricating medium. Aknurled knob 34 is provided for adjusting the quantity of lubricatingmedium, and the cam 35 of this knob cooperates with the flange 36 of themetering piston 26, the position of the knob 34 being indicated by meansof a. pointer 31.

The method of working is the following:

i Starting from the positionshown, when the shaft 3 turns in thedirection of the arrow 33, the pump pistons o and |6 perform a suctionThe feed piston n draws the lubricating oil through the passage |2, orthis oil fiows to the piston, so that the swept space of the piston nand the bore |3 are filled with oil. During the delivery stroke, afterthe passage |2 has been closed, the piston !0 forces a, definitequantity into the delivery bore !3. If the metering piston 26 is so setwith the knob 34 that the return passage 30 is just covered, the piston26 is raised until the outlet 20 is uncovered and the oil delivered bythe piston ID is forced'through the non-return valve 2l and thedischarge 22 into the chamber 23, thus fiowing into the suction passage25 and arriving in the swept space of the piston l6 when the latter israised.

The drawing shows piston 26 in the idling position, at which positionall the oil delivered by the feed pump returns through passage 28 andopenings 29 and 39 to the container. For delivering oil the piston 26 isto be raised and so set by turning the knob 34 that the openings 29 donot coincide with the passage 30. The higher the piston 26 is raised bythe cam 35, i. e. the smaller the stroke of the piston 26 up to theuncovering of the discharge 20, the greater is the quantity oflubricating oil supplied tothe highpressure cylinder ll. If on the otherhand the piston 26 is so far down that the ports 29 are adjacent to thepassage 30, but do not uncover it, the smallest quantity is supplied tothe highpressure pump I 6,' ll, while in the lowest position of thepiston 26 when the ports 29 coincide with the passage 30 (asillustrated) the quantity of oil supplied is returned through the returnpassage 99 into the container I and the high-pressure pump II, I'lreceives no lubricating medium.

During the delivery stroke the high-pressure piston !9 delivers thequantity supplied, after the closing of the suction passage' 25. throughthe passages sia, :Za and the delivery valves 3I, 32

` into the pipe 33 and thus to the subsequent lubricating point. i

The counter-pressure composed of the pipe resistance and the pressure atthe end of the pipe, for instance the compressor pressure, determinesthe pressure of the high-pressure pump. whose piston s remains oii-tightagainst a pressure of more than 1000 atm. abs. The high-pressure pumpcylinder l'l rests against the stop 39 and is fixed in the casing 8 bymeans of the nut 49. The

. guide bus'hing has at its lower end an open connection to thecontainer I through the passage ll In the casing 8 of a set 2 two ormore feed pumps lfl, H and an equal number of high-pressure pumps I 6, I'I might also be arranged, so that a reduction of the distance betweenthe pumps of a set 2 and thus an increase in the total number of pumpsis possible without a change in the length of the apparatus.

I claim:

.1. In a reciprocating pump assembly of the v type including a bodymember, a feed pump cylinder in said body member, a pressure delivery gpump cylinder in said body member, a feed pump piston fitted in saidfeed pump cylinder, a pressure delivery pump piston fltted -in saidpressure delivery pump cylinder, intake openingsin said body memberleading to said cylinders, discharge openings in said body memberleading from said cylinders, passage means interconnecting' thedischarge opening from said feed pump cylinder and the intake opening tosaid pressure delivery pump cylinder, and a spring loaded meteringpiston fitted in said passage means and preventing flow therthroughuntil moved through a predeter-- mined stroke against its springloading, the improvement which -comprises providing a recess in .thepre'ssure face of said metering piston, apassage connecting said recessto the outside of saidfmetering piston behind said face, a vent`-lea'ding outside said body member arrang'ed to connect with' saidpassage at the extreme end position of said metering piston underinfluence of it'sspring loading and means for adjusting th end position'of said metering piston.

v '4 2.'In`the improved assembly of claim 1 the 'further improvementwhich comprises providing as the means for adjusting the end position ofthe meter-ing piston a flange on said metering piston and a helical camengaging said flange.

3. In a reciprocating pump assembly ot the type including a body member,a feed pump cylinder in said body member. a pressure delivery pumpcylinder in said body member. a feed pump piston fitted in said feedpump cylinder, a pressure delivery pump piston fltted in saidpressuredelivery pump cylinder, intake openings in said body member leading tosaid cylinders, discharge openings in said body member leading from'said cylinders, passage means interconnecting the discharge openingsfrom said feed pump cylindeand the intake opening to said pressuredelivery pump cylinder, and a spring loaded metering piston fitted insaid'passage means and preventing flow therethrough until moved througha predetermined stroke against its spring loading, the improvement whichcomprises arranging said pressure delivery pump cylinder to intersectsaid passage means and providing a guide bushing to carry said pressuredelivery pump piston, said guide bushing having an exterior annulargroove which cooper-ates with the walls of said pressure delivery pumpcylinder to form a part of said passage means.

' EUGEN SCHMmT;

REFERENCES CI'I'ED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS 377335 Great Britain' July 28, 1932

